Deep thinking

Martin Rennoldson, Group Account Director at Bombardier, says of the varying train lengths: “There are a lot of variable factors affecting how you boost capacity and we have to solve that equation with an optimal solution.”

Infrastructure will play a part in train size. The Central Line can take trains larger than the Piccadilly, while the line with the smallest clearances is the Waterloo & City. Yet the same train must be able to run on all of them. 

Can Bombardier increase the size of trains that are operating in terms of what’s in use now? Can they be designed to be larger or are they at their limits? Simmons explains: “We’re looking at massively optimising the usable space within the vehicle. And that comes down to clever design.” When he says ‘useable space’, what does he mean? “In the roof area, in the saloon, in the ends themselves, and in the design of the cab,” he says.

Rennoldson elaborates: “It’s about the whole approach to the design of the vehicle interior - ensuring that space for passengers is maximised.” 

There is also experience from Bombardier’s worldwide portfolio. Simmons explains: “Because we’ve got people movers across the world, we’ve got driverless trains across the world. Because of the high levels of reliability that must be achieved, we’re using techniques from the aircraft industry to look at how we can predict when failures are going to occur so that they don’t actually occur on the network - or at all.” Reliability requirements will be exceptional right from delivery. 

When it comes to the NTfL contract, TfL stipulates: “higher performance capability is a core feature of a train system upgrade, and one which has been achieved on several Underground lines over the past two decades.”

The NTfL feasibility stage has investigated provision of ‘more novel features’ for Tube trains. It envisages that: “additional capacity is provided with improved configurations, including walk-through rather than separate carriages, creating more floor area as compared with traditional designs. Passengers can easily transfer between carriages meaning they can distribute throughout the train, avoiding busier carriages where possible. This in turn, will help to reduce dwell times as a more evenly loaded train enables quicker boarding and alighting, passengers can move through the train so they are in the optimal section of the train at their destination station, thus reducing the time spent exiting the system. The provision of a more continuous open space within the vehicle improves security and reduces the opportunity for anti-social behaviour.”

TfL recognises that “the provision of through gangways on a Tube train with traditional configuration is very difficult, if not impossible, due to the dynamic behaviour of the vehicles. Tight curves, in particular, lead to large relative movements between vehicles ends. This means an inter-car gangway would not be possible without removing doors at the end of the carriages, due to the length of the gangway which would be required.” 

It has, however, “identified that it is possible to provide an inter-car gangway by altering the Tube train design so that the relative vertical and lateral movement of the carriage ends can be significantly reduced. This enables a shorter, wide gangway to be fitted without loss of train capacity or a reduction in the number of doors. The re-positioning of the bogies allows all train doors to be double doors. Double doors allow for rapid access, which reduces dwell times. Controlling dwell times becomes a dominant factor for achieving high frequency service levels, due to reduced intervals between trains.”

Returning to the issue of reliability, Rennoldson is keen to point out Bombardier’s testing plans: “We are looking at investing in further testing facilities in the UK and we’re also looking to make additional investments in our bid to win this contract.

“This further investment would be crucial, because we need to run the trains extensively for long periods. Reliability will continue to be a key issue for new train projects, so we’re looking on this as an opportunity to prepare for the future and we feel that it’s a facility worth developing and investing in.”

If Bombardier’s bid is successful, the trains will be built in Derby. Rennoldson points out: “They will be designed in the UK as well. We’re the only firm that can claim that a huge proportion of the engineering and design work will be done here.”

Bombardier is also aligned with the way that TfL works. The industry has changed it says, and for the better, for example enabling suppliers to engage with their customer to gain feedback at an earlier stage. “We’ve been working on this for four years, and that experience has been priceless,” says Simmons. “It’s allowed us to work closely with the client and to scour the globe to ensure we understand the very best and latest technology so we know what is possible from the customer now, and what could be possible in the future. 

“We’ve spent the last two years looking at TfL’s requirements from the ITT and making further suggestions as part of their early supplier engagement. TfL understands that the supply chain has a lot to offer, and we know the Tube and rolling stock very well,” says Simmons.

Knowledge of TfL’s requirements and delivery of its current, high performance rolling stock is inherently advantageous to Bombardier, as Simmons explains: “This long term relationship has been invaluable in growing our experience.”